When spending big dollars on a Super Bowl ad buy, companies would do themselves well to remember that the successful spots aren't just the ones being talked about the next day. The ads that more eyeballs actually saw while watching the game were also worth their weight in focus groups.

For the second year in a row, General Motors is claiming that it aired the most watched ad during the most watched event in U.S. TV history. We are speaking of the 30-second spot entitled "Green Hell" featuring the Cadillac ATS that aired during the game's most tense moments, right after the official two-minute warning was reached. The time was 9:37 PM EST and, according to analysis by Kantar Media, more people were watching NBC's broadcast at that time than any other.

And since this year's Super Bowl was again viewed by another record audience - 111.3 million viewers in the U.S., not to mention over a billion worldwide - the ATS ad therefore becomes the most watched advertisement on television in U.S. history.